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We are committed to monitoring the water quality of the County's lakes to ensure their continued health, as well as the health of the public who utilize the lake's many resources. We invite you to learn more about our program by looking through the pages listed on the left. This site contains detailed graphs of water quality data, photographs of water sampling, and general information about the water quality of King County's lakes


If you have question on this site, please contact Debra Bouchard (206) 477-4650 or Curtis DeGasperi (206) 477-4677

Lake News

Green Lake Warning- Avoid Algae Scum Accumulations

While toxic algae has been found in accumulated scums along the shores of Green Lake, the lake is not closed and remains open to most activities. Look for signs posted along the shoreline. "IF IN DOUBT, STAY ALERT AND STAY OUT!"

Animal Safety Alert - Toxic Algae Blooms

Read this article from the to learn about toxic algae and your pet.